Method of making a reinforced flexible conduit assembly



Dec. 27, 1960 F. S. SCHINDLER ETAL METHOD OF MAKING A REINFORCEDFLEXIBLE CONDUIT ASSEMBLY Original Filed Feb. 13, 1948 2 Sheets-Sheet 111v 17 ml 55m Dec. 27, 1960 F; s. SCHINDLER Er'AL 2,

METHOD OF MAKING A-REINFORCED FLEXIBLE CONDUIT ASSEMBLY- OriginalFiled'Feb. 13, 1948 2 Sheets-s 2 INVENTO (111M fllm/ w i METHOD OFMAKING A REINFORCED FLEXIBLE CONDUIT ASSEMBLY Frank S. Schindler, Berea,and Richard K. Titus, Akron,

Ohio, assignors to Flexonics Corporation, a corporation of IllinoisOriginal application Feb. 13, 1948, Ser. No. 8,116,

now Patent No. 2,644,487, dated July 7, 1953. Divided and thisapplication July 6, 1953, Ser. No.

3 Claims. (Cl. 29-454) This invention relates to a method of makingflexible conduit structures of the type adapted for high pressure use,and concerns particularly the reinforcement means applied to the conduitfor resisting the high pressures.

In the use of flexible conduits, particularly in larger sizes such asexpansion joints, use with high fluid pressures requires thatreinforcing means be applied'to the conduit structure for enabling theflexible member or structure to resist the high pressure forcesinvolved. In certain instances such reinforcing means takes the form ofrings which are disposed in embracing relation to the convolutions ofthe flexible member so as to control the operation of the member and aidin the resisting of internal bursting fluid pressures. In expansionjoints, for example, the flexible member may comprise a thin wallannularly corrugated flexible conduit piece, the annular corrugationsbeing embraced respectively by a series of annular rings suitably shapedto conform to the convolution contours.

In the conventional fabrication of such units the flexible conduit pieceor member is first formed by suitable means, such for example asdrawing, or forming and welding a cylindrical blank from sheet stock,followed by the corrugating operations, such for example as roll ing orother forming operations; after which the reinforcing rings are appliedas complemental half circular pieces suitably bolted together inembracing relation to the formed convolutions. Such fabrication of theunit is costly, and is moreover subject to certain difliculties such forexample as the weakening of the reinforcement rings by the bolt holes,the unbalance of the bolt connections, and other unsatisfactoryconditions induced by the nature and method of assembly of the parts.

In accordance with the present invention the reinforcement rings,heretofore mentioned, are employed as a part of the apparatus or meansby which the corrugating of the flexible member is effected, whereby tosecure economy of fabrication and improved operating characteristics ina number of important particulars, as will hereinafter be pointed out.

Accordingly it is an object of the present invention to provide areinforced flexible conduit structure, of the foregoing type, ofimproved construction and improved operating characteristics.

It is a further object of the invention to provide improved methods andapparatus for efiecting the production of reinforced flexible conduitsof the type defined.

More specifically stated, it is an object of the present invention toprovide an improved reinforced flexible conduit, and methods andapparatus for fabrication, wherein the unit may be more cheaplyfabricated; wherein the reinforcement means will have greater strengthand balance in respect to its size and weight; and wherein a better fitand cooperation is obtained between the reinforcing means and theconvolutions of the flexible member providing increased durability, agreater latitude in manufacturing tolerances, and smoothness ofoperation.

A still further object of the invention is to provide an States Patent Oimproved reinforced flexible conduit in avoidance of the difficultiesheretofore discussed.

Various other objects, advantages and features of the invention will beapparent from the following specification when taken in connection withthe accompanying drawings, wherein certain preferred embodiments are setforth for purposes of illustration.

In the drawings, wherein like reference numerals refer to like partsthroughout:

Fig. 1 is an exploded perspective view of certain of the parts employedin the fabrication of the reinforced flexible conduit, in accordancewith the principles of the present invention, to provide an expansionjoint or structure;

Fig. 2 is a partial illustrative side view of the apparatus employed inmanufacturing the structure of the invention, the parts beingillustrated in one of the initial steps -.of fabrication;

Fig. 3 is a transverse sectional view of the structure of Fig. 2 0n theline 33 thereof;

Fig. 4 is a horizontal sectional view of the structure of Figs. 2 and 3,on the line 4-4 of Fig. 3;

Fig. 5 is a view similar to Fig. 2, showing the parts in a later step offabrication;

Fig. 6 is a longitudinal sectional view of the parts of Fig. 2, on anenlarged scale, and more particularly showing the details ofconstruction;

Fig. 7 is a view similar to Fig. 6 showing a subsequent step in thefabricating operations;

Fig. 8 is a transverse sectional view of the structure of Fig. 7 on theline 8-8 thereof;

Fig. 9 is a partial view, similar to the showings in Fig. 6, butillustrating a modified form of construction;

Figs. 10 and 11 are detail illustrative views showing the end detail ofthe unit as fabricated respectively by the methods of Figs. 6 and 9;

Fig. 12 is a view illustrating a modified form of reinforcement ring;and

Fig. 13 is a view showing the principles of the invention as applied toflexible tubing.

Referring more specifically to the drawings, and first to the embodimentof Figs. 1-7, in Fig. 1 there is illustrated a cylindrical conduit pieceor member It a reinforcement ring 12, and a reinforcement ring 14, theparts being shown in juxtaposed position prior to assembly.

The conduit piece 10 is preferably of suitable metal, plastic or othermaterial having the desired physical properties for the installation tobe made, and may be drawn, or fabricated from flat sheet stock bent intocylindrical shape and, in the case of metal, longitudinally seam weldedas indicated at 16.

Referring to Figs. 2, 3 and 4, a forming apparatus is shown comprising amachine base 18 having frame pedestals 20 and 22 disposed at theopposite ends thereof. The pedestal 20 comprises a lower stationaryportion and a hinged upper portion 24 pivotally mounted upon the lowerportion as indicated at 26, Fig. 3; there being a clamping controlhandle as indicated at 28 for locking and unlocking the upper hingedportion 24 for pivotal movement. Split die or clamping members asindicated at 30 and 32 are carried, respectively, by the lower and upperpedestal members, said clamping dies being removably secured to thepedestals and being of a size and shape in conformance with theparticular conduit structure to be formed.

The pedestal 22 is provided with an upper hinged portion as indicated at34, similar hinged connections and control being provided as in the caseof the parts 26 and 28 previously described. The cooperative pedestalportions 22, 34, however, instead of carrying split die members 30 and32, are cut away to provide an enlarged central opening 36 for a purposeas will presently appear.

A V-shaped guide and support member 38 extends between and is supportedby the fixed pedestals 20, 22, whereas a similarly shaped guide member40 extends between and is supported by the hinged pedestal members 24and 34.

As shown in Figs. 3 and 4, the fixed pedestals also provide support fora pair of spacing or templet bars 42 and 44 provided at opposite sidesof the pedestal structures. More specifically, the templet bars arecarried by a pair of longitudinal frame supports 46, there being pins orbolts 48 upstanding from such supports having slotted interconnectionWith the templet bars so that the templets may be shifted laterallytoward and away from each other.

Referring to Fig. 6, it will be seen that there is provided a clampingplug 50 adapted to be positioned between the cooperative split dies 30and 32. More specifically, the plug member comprises a pair of plates 52and 54 secured together and having interposed therebetween a plate orsheet of rubber 56. The plug is provided with a passage 58interconnecting with a liquid supply conduit 60 leading from a suitablepressure reservoir, and a passage 62 interconnecting with an air escapeor exhaust conduit 64. A bolt 66 extends through the plug, the bolthaving pivoted to its outer end a cam 68 to which is secured a handle70. Arrangement is such that upon manipulation of the handle, the plates52 and 54 may be compressed relatively toward each other so as toradially expand the rubber member 56 into clamping engagement toward thesplit die members 30 and 32.

Referring further to Fig. 6, it Will be seen that the apparatus furthercomprises a second plug member generally indicated by the referencenumeral 72, composed of a pair of metal plates 74 and 76 adapted toclampingly engage an intermediate plate 78 of rubber or the like. A bolt80 operable by a cam 82 and handle 84 is provided for eflecting theradial expansion of the rubber plate 78, as in the case of the plugstructure 50 previously described. The rubber plate 78 cooperates with aring 85 adapted to be arranged in embracing relation therewith. The plug72 is carried by the end of a piston rod 86 adapted to be connected to asuitable cylinder and piston structure (not shown) by which the pistonrod may be power propelled in an axial direction.

In the operation of fabricating the reinforced flexible conduit, inaccordance with the present invention, the cylinder blank is mountedwithin the forming apps.- ratus, as shown in Fig. 2, with thereinforcement rings 12 embracing the blank in predetermined spacedrelation, as shown. In addition to the intermediate rings 12, the numberof which is determined by the length and desired physicalcharacteristics of the completed unit, one end flange reinforcing ring14 is arranged at either end of the structure.

In mounting the cylinder blank 10 and the reinforcement rings 12 and 14into position, the hinged pedestal sections 24 and 34 are raised so asto render the interior of the forming apparatus accessible. The lowersupport trough 38 is so disposed as to properly position the parts, therings 12 and 14 being supported thereon.

To effect the rapid and proper axial placement of the rings, the templetbars 42 and 44 are brought into operative position, as shown in Fig. 4.The inner edges of these bars are notched at proper intervals to spaceand position the reinforcement rings.

The plug members 56) and 72 are next mounted in position, into theopposite ends of the cylinder blank, the ring 85 being arranged inembracing relation to one end of the tube, around the plug 72.

The hinged pedestal sections 24 and 34 may next be lowered, and clamped;and the handles 70 and 84 manipulated to grip the opposite ends of thecylindrical blank.

As will be understood, one end of the blank is clamped in a fluid-tightjoint between the rubber plate 56 and the cooperative die members 30 and32. The opposite end of the blank is gripped in a fluid-tight connectionbetween the rubber expander plate 78 and the ring 85.

The templet bars 42 and 44 are next withdrawn, after which liquid underpressure is introduced into the interior of the cylindrical blank 10 bymeans of the pressure conduit 60 and associated plug passage 58. Trappedair within the blank is relieved through passage 62 and associatedconduit 64, as will be understood. As the hydraulic pressure isintroduced, axial force is also imparted to the piston rod 86, wherebyto effect a radial expansion and axial collapse of the wall sections ofthe blank 10 at spaced intervals, so as to form annular corrugationstherein. The parts are shown prior to the forming operation in Figs. 2and 6, and after the forming in Figs. 5 and 7. During the formingoperation the reinforcing rings 12 move into engagement, as shown inFig. 7, the guide members 33 and 40 being sufliciently spaced when thepedestals are clamped to permit free axial movement of the rings.

As best shown in Figs. 6 and 7, the interior surfaces of the rings 12and 14 are shaped as indicated at 88 so as to impart a predeterminedshaping to the convolution walls as the convolutions are formed.

Upon relief of the hydraulic pressure, withdrawal of the plugs, andopening of the pedestal hinge sections, the assembled expansion unitcomprised of the corrugated blank 16) and the integral rings 12 and 14may be removed from the forming apparatus. To complete the unit each endof the blank 10 may be flanged over onto the end face of its associatedflange member 14, as indicated at 94) in Fig. 10. Also, a slight axialpulling force is imparted to each end of the blank so as to effect aslight separation of the rings as shown at 92.

It will be seen that in accordance with the structures set forth, thereinforcing rings 12 and 14, which remain as a part of the completedunit, are employed also as the forming dies for forming the convolutionsin the cylindrical blank or flexible conduit piece 10. The production ofa reinforced flexible conduit, such for example as an expansion unit, itthus facilitated inasmuch as it is not necessary to assemble reinforcingrings upon the structure after the corrugating operations. Further, thevarious reinforcement rings 12 and 14 are of one piece integralconstruction, the unbalance and weakness of bolt holes and associatedbolt connections being avoided. The rings may thus be made smaller, andlighter in weight, in respect to any required ring strength. Stillfurther, any slight irregularities or imperfections as may be present inthe rings will be reproduced in the associated convolutions 94 of themember 10 cooperable therewith, so that such irregularities andimperfections in effect neutralize themselves and in any event cannotbecome cumulative as may result in instances wherein the convolutionsand the rings are separately formed. A prefect fit between theconvolutions 94 and their associated rein forcing rings is thus insured;while at the same time expensive machining of the rings is not required.

The flanging operation for the end of the flexible cylindrical membermay be avoided by means as illustrated in Fig. 9. In this instance theend flange reinforcing ring as indicated at Ma, corresponding infunction and purpose to the reinforcing ring 14 previously described, isemployed as the reaction base for the rubber clamping plate 56, thesplit die members, such for example as indicated at 32a, being shaped toreceive the ring 14a and to conform thereto. The ring 14a is preferablyin this instance provided with a recess 95 into which an annular portionof the member 10 is projected as the rubber plate 56 is expanded.

If desired, the interconnection between the members 10 and 14a may befurther reinforced by a circular seam resistance weld, as indicated at96 in Fig. 11, the weld being formed after the corrugating operation bysuitable means such as welding rollers 98 and 100.

The present invention particularly lends itself to constructionswherein, due to the requirements of a particular installation, thereinforcing rings may be of different cross section so as to impartpredetermined characteristics of movement to the flexible conduit piece.Thus in Fig. 12 an embodiment is illustrated wherein the intermediatereinforcing rings as indicated respectively at 12a and 12b are ofdifferent cross sectional contour, and resultingly the corrugations inthe flexible member will be differently shaped in conformity thereto. Asin the previously described structures, it will be seen that theconvolutions of the flexible conduit piece will be automatically shapedto conform to the contours of the reinforcing rings, simultaneously asthe rings are nonremovably secured upon the flexible member.

In the structures heretofore described, the reinforced flexible conduitof the invention has been illustrated primarily as embodied into anexpansion joint for conduits and the like. In Fig. 13 a flexible hose ortubing is illustrated embodying the invention. The flexible conduitmember 10 in this instance forms a flexible tube or hose, upon whichthere is assembled the plurality of reinforcing rings as indicated at 12and 14. Due to the fact that the rings are integral, and unimpeded bybolts and the like, it will be seen that they may be readily encompassedwithin a braid 102, the end of which is circular seam resistance weldedas indicated at 104 to a suitable coupling piece 106. The tubing end andthe ring 14 may also be circular seam resistance welded to the couplingas indicated at 108, in a manner similar to the formation of the weld 96previously described. As will be understood, the weld 108 is formedprior to the application of the braid. The rings 12 and 14 may be madeof aluminium or magnesium, whereby to provide a lightweight hosestructure. The rings not only impart.

strength to the tube member 10, resistant to fluid internal pressures,but also act as limiting means for limiting the degree of bendingimparted to any convolution of the tubing whereby to precludeinadvertent rupture or the like. The braid provides resistance to axialelongation due to fluid pressure. Still further, the rings and braidprovide protection for the convolutions of the tubing againstinadvertent hammer knocks and the like. As in the embodiments previouslydescribed, the rings 12 and 14 are employed as dies for forming thetubing convolutions, the dies being non-removably connected to thetubing as an incident to the convolution forming operations. Thestructure of Fig. 13 thus provides a rugged high pressure hose unitwhich may be readily fabricated by means of the rings 12 and 14 whichprovide the dual purposes of reinforcing rings and forming dies. 7 It isobvious that various changes may be made in th specific embodiments setforth without departing from the spirit of the invention. The inventionis accordingly not to be limited to the specific embodiments shown anddescribed, but only as indicated in the following claims. The inventionis hereby claimed as follows: 1. A method of making a reinforcedflexible conduit assembly of a corrugated tube and reinforcing memberscomprising arranging a plurality of one piece ring-like reinforcingmembers along a straight substantially smooth walled tube to becorrugated, spacing said reinforcing members from each other a distanceat least substantially twice as great as the height of the corrugationsto be formed and locating opposite endmost reinforcing members adjacentopposite ends of the tube, sealing opposite ends of the tube,introducing hydraulic liquid into the tube and simultaneously bleedingany air within the tube from the tube while the tube is being filledwith liquid, then applying hydraulic pressure to the liquid within thetube and simultaneously applying an axial compression force to oppositeends of the tube and thereby forming annular corrugations in the tube ofsubstantially greater radial extent than axial extent in the vicinity oftheir junctions with the remainder of the tube and thereby retainingintermediate reinforcing rings on the tube, and securing said endmostreinforcing members to said end portions of the tube.

2. A method, as defined in claim 1, wherein said step of securing saidendmost reinforcing members to said end portions of the tube comprisesannularly resistance welding said endmost reinforcing members to saidend portions of the tube.

3. A method of making a reinforced flexible conduit assembly of acorrugated tube and reinforcing members comprising arranging a pluralityof one piece ring-like reinforcing members along a straightsubstantially smooth walled tube to be corrugated, spacing saidreinforcing members from each other a distance at least substantiallytwice as great as the height of the corrugations to be formed andlocating opposite endmost reinforcing members adjacent opposite ends ofthe tube, sealing opposite ends of the tube, then applying internalhydraulic pressure to the tube and simultaneously applying an axialcompressive force to an opposite end of the tube and thereby expandingthe tube between said reinforcing members and molding the tube againstcomplementary surfaces of said reinforcing members and thereby formingannular corrugations in said tube of greater radial than axial extentand conforming to said complementary surfaces, and thereby retainingsaid reinforcing members on the tube in permanent association therewith.

References Cited in the file of this patent UNITED STATES PATENTS349,718 Hollerith et al Sept. 28, 1886 1,689,620 Clifford Oct. 30, 19281,733,455 Ferrand Oct. 29, 1929 1,835,314 Lord Dec. 8, 1931 1,946,472Babcock Feb. 13, 1934 1,980,264 Giesler "Nov. 13, 1934 2,048,588 BabcockJuly 21. 1936 2,106,496 Debor Jan. 25, 1938 2,115,419 Dreyer Apr. 26,1938 2,323,985 Fausek July 13, 1943 2,345,207 Mansfield Mar. 28, 19442,365,181 Fentress Dec. 19', 1944 2,444,988 Guarnaschelli July 13, 1948r 2,541,869 Grant Feb.'13, 19.51 2,565,184 Parlasca Aug. 21, 19512,610,667 Puster Sept. 16, 1952 2,623,570 Resser Dec. 30, 1952 2,631,640Zallea Mar. 17, 1953 2,635,330 Fentress Apr. 21, 1953 I FOREIGN PATENTS684,910 France Mar. 24, 1930 j OTHER REFERENCES 1 The disclosure in Fig.E on Page 5 of the pamphlet Rex-Flex, published by the Chicago MetalHose Corp., E 15 received by the US. Patent Office on December 23, 1940

